Optical path control member and display device comprising same

ABSTRACT

An optical path control member according to an embodiment comprises: a first substrate; a first electrode disposed on the first substrate; a light conversion part disposed on the first electrode; a second substrate disposed on the first substrate; a second electrode disposed under the second substrate; and an adhesive layer disposed between the light conversion part and the second electrode, wherein the light conversion part comprises alternately disposed partition wall portions and accommodation portions, light transmittance of the accommodation portions changes according to voltage application, the upper surfaces of the partition wall portions are in contact with the adhesive layer, the light conversion part is formed of a photocurable resin, the photocurable resin comprises an oligomer, a monomer, a photopolymerization initiator, and an additive, and the additive comprises an antistatic agent in an amount of 1.5 wt % to 3.0 wt %.

TECHNICAL FIELD

An embodiment relates to an optical path control member, and to adisplay device including the same.

BACKGROUND ART

A light blocking film blocks transmitting of light from a light source,and is attached to a front surface of a display panel which is a displaydevice used for a mobile phone, a notebook, a tablet PC, a vehiclenavigation device, a vehicle touch, etc., so that the light blockingfilm adjusts a viewing angle of light according to an incident angle oflight to express a clear image quality at a viewing angle needed by auser when the display transmits a screen.

In addition, the light blocking film may be used for the window of avehicle, building or the like to shield outside light partially toprevent glare, or to prevent the inside from being visible from theoutside.

That is, the light blocking film may be an optical path control memberthat controls the movement path of light to block light in a specificdirection and transmit light in a specific direction. Accordingly, it ispossible to control the viewing angle of the user by controlling atransmission angle of the light by the light blocking film.

Meanwhile, such a light blocking film may be divided into a lightblocking film that can always control the viewing angle regardless ofthe surrounding environment or the user's environment and a switchablelight blocking film that allow the user to turn on/off the viewing anglecontrol according to the surrounding environment or the user'senvironment.

Such a switchable light blocking film may be implemented by switching apattern part to a light transmitting part and a light blocking part byfilling the inside of the pattern part with particles that may move whena voltage is applied and a dispersion liquid for dispersing theparticles and by dispersing and aggregating the particles.

In order to prevent overflow of a filler, a light conversion part havinga partition wall portion may be manufactured using a photocurable resin.In this case, the photocurable resin may include an additive forimproving releasability or electrical characteristics. Such additivesmay move on a surface of the resin, and thus there is a problem thatoptical characteristics of the resin may deteriorate over time andadhesion between the resin and an adhesive layer may be deteriorated.

Therefore, an optical path control member having a new structure capableof solving the above problems is required.

DISCLOSURE Technical Problem

An embodiment relates to an optical path control member having improvedreliability by improving adhesive properties. In addition, theembodiment may provide an optical path control member with improvedoptical characteristics.

Technical Solution

An optical path control member according to an embodiment includes: afirst substrate; a first electrode disposed on the first substrate; alight conversion part disposed on the first electrode; a secondsubstrate disposed on the first substrate; a second electrode disposedunder the second substrate; and an adhesive layer disposed between thelight conversion part and the second electrode, wherein the lightconversion part includes a partition wall portion and an accommodationportion alternately disposed, the accommodation portion has a lighttransmittance that changes according to application of a voltage, anupper surface of the partition wall portion is in contact with theadhesive layer, the light conversion part is formed of a photocurableresin, the photocurable resin includes an oligomer, a monomer, aphotopolymerization initiator, and an additive, and the additive mayinclude an antistatic agent in an amount of 2.0 wt % to 3.0 wt %.

Advantageous Effects

An optical path control member according to an embodiment can improveadhesive properties of an adhesive layer bonding a first substrate and asecond substrate.

The embodiment may improve adhesion between a partition wall portion andthe adhesive layer by changing a composition of a photocurable resinused in order to accommodate a light conversion material and preventoverflow of the light conversion material. In detail, the embodiment canreduce a content of an additive included in order to improvereleasability or electrical characteristics of the photocurable resin.Accordingly, the embodiment can prevent film removal or delaminationbetween the partition wall portion and the adhesive layer according tomovement of the additive included in the resin.

In addition, the embodiment can prevent deterioration of opticalcharacteristics due to movement of additives in the photocurable resinto a surface of the photocurable resin over time. That is, theembodiment can prevent haze change over time by optimizing a materialand content of the additive used to form the partition wall portion.

Accordingly, the optical characteristics and durability of the opticalpath control member and a display device including the same can beimproved.

DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 are perspective views of an optical path control memberaccording to an embodiment.

FIGS. 3 and 4 are a perspective view of a first substrate and a firstelectrode and a perspective view of a second substrate and a secondelectrode of the optical path control member according to theembodiment.

FIG. 5 is a cross-sectional view taken along line A-A′ in FIG. 1 .

FIGS. 6 and 9 are cross-sectional views taken along line A-A′ in FIG. 1for describing shapes of various accommodation portions in the opticalpath control member according to the embodiment.

FIG. 10 is a view showing an example of a principle that an additiveadheres to a surface of a partition wall portion in a dispersion liquid.

FIG. 11 is a schematic diagram of dispersion of carbon black andformation of micelles.

FIG. 12 a is a view showing parts of a head and tail according to a typeof surfactant, and FIG. 12 b is a view showing an example of asurfactant.

FIG. 13 is a view showing an example of a micellar form of a nonionicsurfactant and a micellar form of an anionic surfactant.

FIGS. 14 to 20 are views for describing a method of manufacturing anoptical path control member according to an embodiment.

FIGS. 21 and 22 are cross-sectional views of a display device to whichan optical path control member according to an embodiment is applied.

FIGS. 23 to 25 are views for describing one embodiment of the displaydevice to which the optical path control member according to theembodiment is applied.

MODES OF THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings. However, the spiritand scope of the present invention is not limited to a part of theembodiments described, and may be implemented in various other forms,and within the spirit and scope of the present invention, one or more ofthe elements of the embodiments may be selectively combined andreplaced.

In addition, unless expressly otherwise defined and described, the termsused in the embodiments of the present invention (including technicaland scientific terms) may be construed the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs, and the terms such as those defined in commonly useddictionaries may be interpreted as having a meaning that is consistentwith their meaning in the context of the relevant art.

In addition, the terms used in the embodiments of the present inventionare for describing the embodiments and are not intended to limit thepresent invention. In this specification, the singular forms may alsoinclude the plural forms unless In detail stated in the phrase, and mayinclude at least one of all combinations that may be combined in A, B,and C when described in “at least one (or more) of A (and), B, and C”.

Further, in describing the elements of the embodiments of the presentinvention, the terms such as first, second, A, B, (a), and (b) may beused. These terms are only used to distinguish the elements from otherelements, and the terms are not limited to the essence, order, or orderof the elements.

In addition, when an element is described as being “connected”, or“coupled” to another element, it may include not only when the elementis directly “connected” to, or “coupled” to other elements, but alsowhen the element is “connected”, or “coupled” by another element betweenthe element and other elements.

Further, when described as being formed or disposed “on (over)” or“under (below)” of each element, the “on (over)” or “under (below)” mayinclude not only when two elements are directly connected to each other,but also when one or more other elements are formed or disposed betweentwo elements.

Furthermore, when expressed as “on (over)” or “under (below)”, it mayinclude not only the upper direction but also the lower direction basedon one element.

Hereinafter, an optical path control member according to an embodimentwill be described with reference to drawings. The optical path controlmember described below relates to a switchable optical path controlmember driven in various modes according to electrophoretic particlesmoving by application of a voltage.

Referring to FIGS. 1 to 4 , an optical path control member 1000according to an embodiment may include a first substrate 110, a secondsubstrate 120, a first electrode 210, a second electrode 220, and alight conversion part 300.

The first substrate 110 may support the first electrode 210. The firstsubstrate 110 may be rigid or flexible.

In addition, the first substrate 110 may be transparent. For example,the first substrate 110 may include a transparent substrate capable oftransmitting light.

The first substrate 110 may include glass, plastic, or a flexiblepolymer film. For example, the flexible polymer film may be made of anyone of polyethylene terephthalate (PET), polycarbonate (PC),acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate(PMMA), polyethylene naphthalate (PEN), polyether sulfone (PES), cyclicolefin copolymer (COC), triacetylcellulose (TAC) film, polyvinyl alcohol(PVA) film, polyimide (PI) film, and polystyrene (PS), which is only anexample, but the embodiment is not limited thereto.

In addition, the first substrate 110 may be a flexible substrate havingflexible characteristics.

Further, the first substrate 110 may be a curved or bended substrate.That is, the optical path control member including the first substrate110 may also be formed to have flexible, curved, or bentcharacteristics. Accordingly, the optical path control member accordingto the embodiment may be changed to various designs.

The first substrate 110 may extend in a first direction 1A, a seconddirection 2A, and a third direction 3A.

In detail, the first substrate 110 may include the first direction 1Acorresponding to a length or width direction of the first substrate 110,a second direction 2A extending in a direction different from the firstdirection 1A and corresponding to the length or width direction of thefirst substrate 110, and a third direction 3A extending in a directiondifferent from the first direction 1A and the second direction 2A andcorresponding to a thickness direction of the first substrate 110.

For example, the first direction 1A may be defined as the lengthdirection of the first substrate 110, the second direction 2A may bedefined as the width direction of the first substrate 110 perpendicularto the first direction 1A, and the third direction 3A may be defined asthe thickness direction of the first substrate 110. Alternatively, thefirst direction 1A may be defined as the width direction of the firstsubstrate 110, the second direction 2A may be defined as the lengthdirection of the first substrate 110 perpendicular to the firstdirection 1A, and the third direction 3A may be defined as the thicknessdirection of the first substrate 110.

Hereinafter, for convenience of description, the first direction 1A willbe described as the length direction of the first substrate 110, thesecond direction 2A will be described as the width direction of thefirst substrate 110, and the third directions 3A will be described asthe thickness direction of the first substrate 110.

The first electrode 210 may be disposed on one surface of the firstsubstrate 110. In detail, the first electrode 210 may be disposed on anupper surface of the first substrate 110. That is, the first electrode210 may be disposed between the first substrate 110 and the secondsubstrate 120.

The first electrode 210 may include a transparent conductive material.For example, the first electrode 210 may include a conductive materialhaving a light transmittance of about 80% or more.

As an example, the first electrode 210 may include a metal oxide such asindium tin oxide, indium zinc oxide, copper oxide, tin oxide, zincoxide, titanium oxide, etc.

The first electrode 210 may have a thickness of 0.05 μm to 2 μm.

Alternatively, the first electrode 210 may include various metals torealize low resistance. For example, the first electrode 210 may includeat least one metal of chromium (Cr), nickel (Ni), copper (Cu), aluminum(Al), silver (Ag), molybdenum (Mo). Gold (Au), titanium (Ti), and alloysthereof.

Referring to FIG. 3 , the first electrode 210 may be disposed on theentire surface of one surface of the first substrate 110. In detail, thefirst electrode 210 may be disposed as a surface electrode on onesurface of the first substrate 110. However, the embodiment is notlimited thereto, and the first electrode 210 may be formed of aplurality of pattern electrodes having a uniform pattern such as a meshor stripe shape.

For example, the first electrode 210 may include a plurality ofconductive patterns. In detail, the first electrode 210 may include aplurality of mesh lines crossing each other and a plurality of meshopenings formed by the mesh lines.

Accordingly, even though the first electrode 210 includes a metal, thefirst electrode 210 is not visually recognized from the outside, so thatvisibility may be improved. In addition, the light transmittance isincreased by the openings, so that the brightness of the optical pathcontrol member according to the embodiment may be improved.

The second substrate 120 may be disposed on the first substrate 110. Indetail, the second substrate 120 may be disposed on the first electrode210 on the first substrate 110.

The second substrate 120 may include a material capable of transmittinglight. The second substrate 120 may include a transparent material. Thesecond substrate 120 may include a material the same as or similar tothat of the first substrate 110 described above.

For example, the second substrate 120 may include glass, plastic, or aflexible polymer film. For example, the flexible polymer film may bemade of any one of polyethylene terephthalate (PET), polycarbonate (PC),acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate(PMMA), polyethylene naphthalate (PEN), polyether sulfone (PES), cyclicolefin copolymer (COC), triacetylcellulose (TAC) film, polyvinyl alcohol(PVA) film, polyimide (PI) film, and polystyrene (PS). This is only anexample, but the embodiment is not limited thereto.

In addition, the second substrate 120 may be a flexible substrate havingflexible characteristics.

Further, the second substrate 120 may be a curved or bended substrate.That is, the optical path control member including the second substrate120 may also be formed to have flexible, curved, or bentcharacteristics. Accordingly, the optical path control member accordingto the embodiment may be changed to various designs.

The second substrate 120 may also extend in the first direction 1A, thesecond direction 2A, and the third direction 3A in the same manner asthe first substrate 110 described above.

In detail, the second substrate 120 may include the first direction 1Acorresponding to a length or width direction of the second substrate120, the second direction 2A extending in a direction different from thefirst direction 1A and corresponding to the length or width direction ofthe second substrate 120, and the third direction 3A extending in thedirection different from the first direction 1A and the second direction2A and corresponding to the thickness direction of the second substrate120.

For example, the first direction 1A may be defined as the lengthdirection of the second substrate 120, the second direction 2A may bedefined as the width direction of the second substrate 120 perpendicularto the first direction 1A, and the third direction 3A may be defined asthe thickness direction of the second substrate 120.

Alternatively, the first direction 1A may be defined as the widthdirection of the second substrate 120, the second direction 2A may bedefined as the length direction of the second substrate 120perpendicular to the first direction 1A, and the third direction 3A maybe defined as the thickness direction of the second substrate 120.

Hereinafter, for convenience of description, the first direction 1A willbe described as the length direction of the second substrate 120, thesecond direction 2A the second direction 2A will be described as thewidth direction of the second substrate 120, and the third directions 3Awill be described as the thickness direction of the second substrate120.

The second electrode 220 may be disposed on one surface of the secondsubstrate 120. In detail, the second electrode 220 may be disposed on alower surface of the second substrate 120. That is, the second electrode220 may be disposed on one surface of the second substrate 120 in whichthe second substrate 120 and the first substrate 110 face each other.That is, the second electrode 220 may be disposed to face the firstelectrode 210 on the first substrate 110. That is, the second electrode220 may be disposed between the first electrode 210 and the secondsubstrate 120.

The second electrode 220 may include a material the same as or similarto that of the first substrate 110 described above.

The second electrode 220 may include a transparent conductive material.For example, the second electrode 220 may include a conductive materialhaving a light transmittance of about 80% or more. As an example, thesecond electrode 220 may include a metal oxide such as indium tin oxide,indium zinc oxide, copper oxide, tin oxide, zinc oxide, titanium oxide,etc.

The second electrode 220 may have a thickness of about 0.1 μm to about0.5 μm.

Alternatively, the second electrode 220 may include various metals torealize low resistance. For example, the second electrode 220 mayinclude at least one metal of chromium (Cr), nickel (Ni), copper (Cu),aluminum (Al), silver (Ag), molybdenum (Mo). gold (Au), titanium (Ti),and alloys thereof.

Referring to FIG. 4 , the second electrode 220 may be disposed on theentire surface of one surface of the second substrate 120. In detail,the second electrode 220 may be disposed as a surface electrode on onesurface of the second substrate 120. However, the embodiment is notlimited thereto, and the second electrode 220 may be formed of aplurality of pattern electrodes having a uniform pattern such as a meshor stripe shape.

For example, the second electrode 220 may include a plurality ofconductive patterns. In detail, the second electrode 220 may include aplurality of mesh lines crossing each other and a plurality of meshopenings formed by the mesh lines.

Accordingly, even though the second electrode 220 includes a metal, thesecond electrode 220 is not visually recognized from the outside, sothat visibility may be improved. In addition, the light transmittance isincreased by the openings, so that the brightness of the optical pathcontrol member according to the embodiment may be improved.

The first substrate 110 and the second substrate 120 may have sizescorresponding to each other. The first substrate 110 and the secondsubstrate 120 may have sizes the same as or similar to each other.

In detail, a first length extending in the first direction 1A of thefirst substrate 110 may have a size the same as or similar to a secondlength L2 extending in the first direction 1A of the second substrate120.

For example, the first length and the second length may have a size of300 mm to 400 mm.

In addition, a first width extending in the second direction 2A of thefirst substrate 110 may have a size the same as or similar to a secondwidth extending in the second direction 2A of the second substrate 120.

For example, the first width and the second width may have a size of 150mm to 200 mm.

In addition, a first thickness extending in the third direction 3A ofthe first substrate 110 may have a size the same as or similar to asecond thickness extending in the third direction 3A of the secondsubstrate 120.

For example, the first thickness and the second thickness may have asize of 30 μm to 200 μm.

Referring to FIG. 1 , the first substrate 110 and the second substrate120 may be disposed to be misaligned from each other.

In detail, the first substrate 110 and the second substrate 120 may bedisposed at positions misaligned from each other in the first direction1A. In detail, the first substrate 110 and the second substrate 120 maybe disposed so that side surfaces of the substrates are misaligned fromeach other.

Accordingly, the first substrate 110 may be disposed to protrude in onedirection in the first direction 1A, and the second substrate 120 may bedisposed to protrude in the other direction in the second direction 2A.

That is, the first substrate 110 may include a first protrusionprotruding in one direction in the first direction 1A, and the secondsubstrate 110 may include a second protrusion protruding in the otherdirection in the first direction 1A.

Accordingly, the optical path control member 1000 may include a regionwhere the first electrode 210 is exposed on the first substrate 110 anda region where the second electrode 220 is exposed under the secondsubstrate 120.

That is, the first electrode 210 disposed on the first substrate 110 maybe exposed at the first protrusion, and the second electrode 220disposed under the second substrate 120 may be exposed at the secondprotrusion.

The first electrode 210 and the second electrode 220 exposed at theprotrusions may be connected to an external printed circuit boardthrough a connection portion that will be described below.

Alternatively, referring to FIG. 2 , the first substrate 110 and thesecond substrate 120 may be disposed at positions corresponding to eachother. In detail, the first substrate 110 and the second substrate 120may be disposed so that each side surface corresponds to each other.

Accordingly, the first substrate 110 may be disposed to protrude in onedirection of the first direction 1A, and the second substrate 120 mayalso be disposed to protrude in one direction of the first direction 1A,that is, in the same direction as the first substrate 110.

That is, the first substrate 110 may include the first protrusionprotruding in one direction in the first direction 1A, and the secondsubstrate may also include the second protrusion protruding in onedirection in the first direction 1A.

That is, the first protrusion and the second protrusion may protrude inthe same direction.

Accordingly, the optical path control member 1000 may include the regionwhere the first electrode 210 is exposed on the first substrate 110 andthe region where the second electrode 220 is exposed under the secondsubstrate 120.

That is, the first electrode 210 disposed on the first substrate 110 maybe exposed at the first protrusion, and the second electrode 220disposed under the second substrate 120 may be exposed at the secondprotrusion.

The first electrode 210 and the second electrode 220 exposed at theprotrusions may be connected to the external printed circuit boardthrough the connection portion that will be described below.

The light conversion part 300 may be disposed between the firstsubstrate 110 and the second substrate 120. In detail, the lightconversion part 300 may be disposed between the first electrode 210 andthe second electrode 220.

An adhesive layer or a buffer layer may be disposed between at least oneof between the light conversion part 300 and the first substrate 110 orbetween the light conversion part 300 and the second substrate 120, andthe first substrate 110, the second substrate 120, and the lightconversion part 300 may be adhered to each other by the adhesive layerand/or the buffer layer.

The light conversion part 300 may include a plurality of partition wallportions and accommodation portions. Light conversion particles thatmove according to application of a voltage may be disposed in theaccommodation portion, and light transmission characteristics of theoptical path control member may be changed by the light conversionparticles.

A size of the light conversion part 300 may be smaller than a size of atleast one of the first substrate 110 and the second substrate 120.

In detail, a length of the light conversion part 300 in the firstdirection may be smaller than a length of at least one of the firstsubstrate 110 and the second substrate 120 in the first direction.

In addition, a width of the light conversion part 300 in the seconddirection may be the same as or smaller than a width of at least one ofthe first substrate 110 and the second substrate 120 in the seconddirection.

In addition, at least one of both ends of the first substrate 110 andthe second substrate 120 in the first direction may be disposed outsideboth ends of the light conversion part 300 in the first direction.

Accordingly, a sealing portion (not shown in the drawing) may be easilydisposed, and the adhesive properties of the sealing portion may beimproved.

An optical path control member according to an embodiment will bedescribed with reference to FIG. 5 .

The optical path control member according to the embodiment may includea light conversion material. For example, the light conversion material320′ may be an EPD ink. In order to accommodate the light conversionmaterial 320′ and prevent overflow thereof, the light conversion part300 may be used. The light conversion part 300 may include anaccommodation portion 320 for accommodating the light conversionmaterial 320′ and a partition wall portion 310 for preventing the lightconversion material 320′ from overflowing.

The light conversion part 300 may be formed of a photocurable resin. Forexample, the light conversion part 300 may be formed by imprinting thephotocurable resin. That is, the partition wall portion 310 and theaccommodation portion 320 may be formed of the photocurable resin.

In detail, the partition wall portion 310 may include a resin material.For example, the partition wall portion 310 may include a photocurableresin material. As an example, the partition wall portion 310 mayinclude a urethane resin or the like.

The photocurable resin may include urethane acrylate, an acrylatemonomer, isobornyl acrylate, an additive, a photoinitiator, andacryloylmorpholine. For example, the photoinitiator may include1-Hydroxycyclohexyl Phenylmethanone.

The photocurable resin may include an oligomer, a monomer, aphotopolymerization initiator, and an additive. The photocurable resinmay form the light conversion part by reaction of a polymer-typeprepolymer, a polyfunctional monomer as a diluent, and aphotopolymerization initiator.

Here, the additive may be various materials added to improve the drivingspeed of a device. For example, the additive may be a material that maybe applied to the photocurable resin to increase the driving speed ofthe EPD ink. Here, the additive may refer to various materials forimproving releasability or electrical characteristics of thephotocurable resin. For example, the additive may refer to variousmaterials including a release additive and/or an antistatic agent.

However, when such an additive is excessively added, a problem that hazeincreases at an interface of the resin layer and transmittance decreasesmay occur. In addition, the additive has a property of moving to asurface of the resin over time. Such movement of the additive may causea problem of deteriorating the optical characteristics of the opticalpath control member. In addition, the movement of the additive maydeteriorate adhesion between the additive and the partition wallportion.

The embodiment may optimize a content of the additive included in thephotocurable resin forming the partition wall portion in order to reducethe movement of the additive. Accordingly, the embodiment may improveoptical characteristics by reducing haze and increasing transmittance.In addition, the embodiment may improve the adhesion between theadhesive layer and the partition wall portion by optimizing the contentof the additive.

With reference to Table 1, changes in haze and transmittance accordingto types and contents of additives in Examples 1 to 3 will be described.

When a weight of the photocurable resin is 100 wt %, the additive may beincluded in an amount of 5.0 wt % or less. In detail, when a weight ofthe photocurable resin is 100 wt %, the additive may be included in 2.0wt % to 3.0 wt %. In the embodiment, since the additive in thephotocurable resin is included in an amount of 5.0 wt % or less, theamount of the additive moving to the surface of the resin may bereduced.

The additive may include the antistatic agent in an amount of 1.5 wt %to 3.0 wt %. For example, the additive may include the antistatic agentin an amount of 2.0 wt % to 3.0 wt %. For example, the additive mayinclude the antistatic agent in an amount of 2.4 wt % to 2.7 wt %.

In Example 1, the photocurable resin forming the light conversion partmay include the antistatic agent as an additive in an amount of 2.0 wt %to 3.0 wt %.

The antistatic agent may be included in the photocurable resin toimprove conductivity. The antistatic agent may help improve electricalconductivity by lowering a volume resistance and surface resistance. Theantistatic agent may use a material or an ionic compound having highcharge mobility to implement antistatic effect by moving an electriccharge accumulated on a surface or inside of a component to an externalconductive material (moisture). That is, the antistatic agent mayimprove driving characteristics of the electric charge transferred tothe surface.

When the antistatic agent is included in the photocurable resin in anamount of 2.0 wt % to 3.0 wt %, it is possible to prevent movement ofthe additive to the resin surface, thereby reducing haze. In detail,when the antistatic agent is contained in an amount of 2.0 wt % to 3.0wt % in the photocurable resin, the haze may be 9% or less.

For example, the photocurable resin of the embodiment may include theantistatic agent in an amount of 2.0 wt % to 3.0 wt %, so that the hazemay be 5% or less. For example, the photocurable resin of the embodimentmay include the antistatic agent in an amount of 2.0 wt % to 3.0 wt %,so that the haze may be 3% or less.

When the antistatic agent is included in the photocurable resin in anamount of 2.0 wt % to 3.0 wt %, a lateral transmittance of the opticalpath control member and a display device including the same may beincreased. In the embodiment, the antistatic agent may be included inthe photocurable resin in an amount of 2.0 wt % to 3.0 wt %, therebyimproving the lateral transmittance to 30% or more. In detail, in theembodiment, the antistatic agent may be included in the photocurableresin in an amount of 2.0 wt % to 3.0 wt %, thereby improving thelateral transmittance to 33% to 37%.

Here, the lateral transmittance is measured in a share mode and mayrefer to a luminance value measured when the device is positioned at 45degrees. That is, the lateral transmittance is that the luminance valueof the device positioned at the 45 degrees is measured in a measuringdevice.

In detail, the lateral transmittance of the optical path control membermay be defined as a light transmittance measured by (B/A)*100 aftermeasuring a luminance (A) of light emitted from a light source in astate in which the optical path control member is not disposed and aluminance (B) of light emitted at an angle of 45° through the opticalpath control member in the light source in a state in which the opticalpath control member is disposed on the light source.

When the antistatic agent is included in an amount greater than 3.0 wt%, there is a problem of deteriorating the optical characteristics ofthe resin and deteriorating the adhesive performance. In detail, whenthe antistatic agent is included in the amount of greater than 3.0 wt %in the photocurable resin, haze of the resin may be increased, andadhesion between the light conversion part and the adhesive layer may bedeteriorated.

As an example, when the antistatic agent is included in the amount ofgreater than 3.0 wt %, the haze may rapidly increase to 60% to 70%. Inaddition, when the antistatic agent is included in the amount greaterthan 3.0 wt %, the lateral transmittance may be less than 30%. Indetail, when the antistatic agent is included in the amount of more than3.0 wt %, the lateral transmittance may show 17% to 26%.

When the antistatic agent is included in an amount of less than 2.0 wt%, the driving speed of the optical path control member and the displaydevice including the same may be reduced.

The antistatic agent may include a surfactant.

The antistatic agent may include at least one of conductive carbon, aconductive inorganic material such as metal particles, a conductivepolymer, and a surfactant. For example, the embodiment may include thesurfactant as an antistatic agent. Accordingly, the embodiment mayincrease the driving speed even by using a small amount of additive. Inaddition, the surfactant has an advantage of low cost. The conductiveinorganic material has disadvantages that a mixing process is difficult,particles may be generated, and the price is high. In addition, theconductive polymer has a problem in color realization and the like.

The surfactant may include at least one of a nonionic surfactant, acationic surfactant, an anionic surfactant, and an amphotericsurfactant. The nonionic surfactant may include an amine-basedsurfactant or a glycerin-based surfactant. The cationic surfactant mayinclude a quaternary ammonium salt. The anionic surfactant may includesulfonate and phosphate. The amphoteric surfactant may include betaine.

Here, the additive may further include a non-reactive release additivehaving a form of a siloxane product. As an example, the non-reactiverelease additive may be a Si-containing material such as PDMS.

The non-reactive release additive may include a material in which afunctional group is bonded to polydimethylsiloxane. The non-reactiverelease additive may include a material in which one or more functionalgroups are bonded to polydimethylsiloxane. The non-reactive releaseadditive may include a material in which two or more functional groupsthat are the same or different from each other are bonded topolydimethylsiloxane.

The non-reactive release additive may be a functional fluid in which afunctional group is bonded to polydimethylsiloxane. In detail, thefunctional group bonded to a backbone of polydimethylsiloxane mayinclude various materials such as alkyl, aryl, allyl, alkenyl, amido,amino, fluoroalkyl, halide, epoxy, carboxyl, hydroxyl, alkoxy,methylhydrogen, and the like. In addition, copolymer containing Si mayinclude siloxane-urethane copolymer, siloxane-polycaponate copolymer,siloxane-polyester copolymer, siloxane-polyimide copolymer,acryloxymethylsiloxane, p-styrylsiloxane, copolymer of silicone andaldehyde, polysilformal, and the like.

In Example 2, the additive may include the non-reactive release additivein an amount of 0.3 wt % or less.

The photocurable resin of the embodiment may include the non-reactiverelease additive in an amount of 0.3 wt % or less. For example, thephotocurable resin of the embodiment may include the non-reactiverelease additive in an amount of 0.1 wt % to 0.2 wt %. In detail, in theembodiment, the non-reactive release additive is included in thephotocurable resin in an amount of 0.1 wt % to 0.2 wt %, thereby showinga haze value of 9% or less. In detail, in the embodiment, thenon-reactive release additive is included in the photocurable resin inan amount of 0.1 wt % to 0.2 wt %, thereby showing a haze value of 5% orless. In detail, in the embodiment, the non-reactive release additive isincluded in the photocurable resin in an amount of 0.1 wt % to 0.2 wt %,thereby showing a haze value of 3% or less. In addition, in theembodiment, the non-reactive release additive is included in thephotocurable resin in an amount of 0.1 wt % to 0.2 wt %, so that theoptical path control member and the display device including the samemay show a lateral transmittance of 30% or more. In detail, in theembodiment, the non-reactive release additive is included in thephotocurable resin in an amount of 0.1 wt % to 0.2 wt %, so that theoptical path control member and the display device including the samemay show a lateral transmittance of 33% to 37%.

When the non-reactive release additive is included in the photocurableresin in an amount of less than 0.1 wt %, the release property may bedeteriorated, and productivity or process efficiency may be deterioratedwhen the resin layer is formed by imprinting.

When the non-reactive release additive is included in the photocurableresin in an amount of more than 0.3 wt %, haze may rapidly increase. Asan example, when the non-reactive release additive is included in thephotocurable resin in an amount of more than 0.3 wt %, the haze may be40% to 50%.

In Example 3, the photocurable resin forming the light conversion partmay include an antistatic agent and a non-reactive release additive inan amount of 2.4 wt % to 2.8 wt % as an additive. For example, in theembodiment, the photocurable resin may include 0.05 wt % to 0.2 wt % ofa non-reactive release additive and 2.4 wt % to 2.7 wt % of anantistatic agent as an additive. In Example 2, as the two additives areadded in an optimal content, all of the releasability, adhesion, drivingspeed, and transmittance may be improved. In Example 3, a lateraltransmittance value may be improved compared to Example 1 or Example 2in which any one of the release additive and the antistatic agent isadded.

In the embodiment, an antistatic agent and a non-reactive releaseadditive as an additive may be included in the photocurable resin in anamount of 2.4 wt % to 2.8 wt %, so that the haze may be 9% or less. Forexample, in the embodiment, the antistatic agent and the non-reactiverelease additive as the additive may be included in the photocurableresin in an amount of 2.4 wt % to 2.8 wt %, so that the haze may be 5%or less. For example, in the embodiment, the antistatic agent and thenon-reactive release additive as the additive may be included in thephotocurable resin in an amount of 2.4 wt % to 2.8 wt %, so that thehaze may be 3% or less.

In the embodiment, the antistatic agent and the non-reactive releaseadditive as the additive may be included in the photocurable resin in anamount of 2.4 wt % to 2.8 wt %, so that the lateral transmittance of theoptical path control member and the display device including the samemay be 30% or more.

For example, in the embodiment, the antistatic agent and thenon-reactive release additive as the additive may be included in thephotocurable resin in an amount of 2.4 wt % to 2.8 wt %, so that thelateral transmittance of the optical path control member and the displaydevice including the same may be 35% or more. For example, in theembodiment, the antistatic agent and the non-reactive release additiveas the additive may be included in the photocurable resin in an amountof 2.4 wt % to 2.8 wt %, so that the lateral transmittance of theoptical path control member and the display device including the samemay be 37% to 41%.

Meanwhile, when the additive is not included, it is possible to show aproblem that the lateral transmittance of the display device includingthe photocurable resin may be less than 5%.

TABLE 1 Comparative Example 1 Example 2 Example 3 Example 1 Non-reactive— 0.1~0.2 0.05~0.2  — release additive (wt %) Antistatic agent 2.0~3.0 —2.4~2.7 — (wt %) Haze (%) 2.3~8.6 1.5~5.0 1.9~8.5 — Lateral 33~37 33~3737~41 3.2~4.8 transmittance (%)

In the embodiment, it can be confirmed that the content of the additiveaccording to the position of the partition wall portion by measuring XPSfrom an interface between an upper surface 310T of the partition wallportion and a lower surface 420B of the adhesive layer in a depthdirection of the partition wall portion. The partition wall portion 310may be divided into a first region that is a surface part of the resin,a second region that is an intermediate part, and a third region that isa base layer part according to the depth thereof. In detail, thepartition wall portion may include a first region P1 from the uppersurface 310T of the partition wall portion to 30 μm in the depthdirection, a second region P2 from 30 μm to 60 μm from the upper surfaceof the partition wall portion in the depth direction, and a third regionP3 from 60 μm to 95 μm from the upper surface of the partition wallportion in the depth direction.

In an embodiment, an Si content in the first region may be reduced.Accordingly, it is possible to prevent film removal of the adhesivelayer on a surface of the resin layer.

Details of the light conversion part 300 will be described in detailbelow.

Referring to FIGS. 5 to 9 , the light conversion part 300 may include apartition wall portion 310, and an accommodation portion 320.

The partition wall portion 310 may be defined as a partition wallportion dividing the accommodation portion. That is, the partition wallportion 310 may transmit light as a barrier region dividing a pluralityof accommodation portions. In addition, the accommodation portion 320may be defined as a variable region where the accommodation portion 320is switched to a light blocking part and a light transmitting partaccording to application of a voltage.

The partition wall portion 310 and the accommodation portion 320 may bealternately disposed with each other. The partition wall portion 310 andthe accommodation portion 320 may be disposed to have different widths.For example, a width of the partition wall portion 310 may be greaterthan that of the accommodation portion 320.

The partition wall portion 310 and the accommodation portion 320 may bealternately disposed with each other. In detail, the partition wallportion 310 and the accommodation portion 320 may be alternatelydisposed with each other. That is, each of the partition wall portions310 may be disposed between the accommodation portions 320 adjacent toeach other, and each of the accommodation portions 320 may be disposedbetween the adjacent partition wall portions 310.

The partition wall portion 310 may include a transparent material. Thepartition wall portion 310 may include a material that may transmitlight.

The partition wall portion 310 may transmit light incident on any one ofthe first substrate 110 and the second substrate 120 toward anothersubstrate.

For example, in FIGS. 6 and 9 , light may be emitted from the firstsubstrate 110 by a light source disposed under the first substrate 110,and the light may be incident toward the second substrate 120. In thiscase, the partition wall portion 310 may transmit the light, and thetransmitted light may move toward the second substrate 120.

The accommodation portion 320 may include the dispersion liquid 320 aand the light conversion particles 320 b. In detail, the accommodationportion 320 may be filled by injecting the dispersion liquid 320 a. Aplurality of light conversion particles 320 b may be dispersed in thedispersion liquid 320 a.

The dispersion liquid 320 a may be a material for dispersing the lightconversion particles 320 b. The dispersion liquid 320 a may include atransparent material. The dispersion liquid 320 a may include anon-polar solvent. In addition, the dispersion liquid 320 a may includea material capable of transmitting light. For example, the dispersionliquid 320 a may include at least one of a halocarbon-based oil, aparaffin-based oil, and isopropyl alcohol.

The light conversion particles 320 b may be disposed to be dispersed inthe dispersion liquid 320 a. In detail, the plurality of lightconversion particles 320 b may be disposed to be spaced apart from eachother in the dispersion liquid 320 a.

The dispersion liquid 320 a may further include an additive. Theadditive included in the dispersion liquid 320 a will be described indetail below.

The light conversion particles 320 b may include a material capable ofabsorbing light. That is, the light conversion particles 320 b may belight absorbing particles. The light conversion particles 320 b may havea color. For example, the light conversion particles 320 b may have ablack-based color. As an example, the light conversion particles 320 bmay include carbon black.

The light conversion particles 320 b may have a polarity by charging asurface thereof. For example, the surface of the light conversionparticles 320 b may be charged with a negative (−) charge. Accordingly,according to the application of the voltage, the light conversionparticles 320 b may move toward the first electrode 210 or the secondelectrode 220.

The light transmittance of the accommodation portion 320 may be changedby the light conversion particles 320 b. In detail, the accommodationportion 320 may be switched to the light blocking part and the lighttransmitting part by changing the light transmittance due to themovement of the light conversion particles 320 b. That is, theaccommodation portion 320 may change the transmittance of light passingthrough the accommodation portion 320 by dispersion and aggregation ofthe light conversion particles 320 b disposed inside the dispersionliquid 320 a.

For example, the optical path control member according to the embodimentmay be converted from a first mode to a second mode or from the secondmode to the first mode by a voltage applied to the first electrode 210and the second electrode 220.

In detail, in the optical path control member according to theembodiment, the accommodation portion 320 becomes the light blockingpart in the first mode, and light of a specific angle may be blocked bythe accommodation portion 320. That is, a viewing angle of the userviewing from the outside is narrowed, so that the optical path controlmember may be driven in a privacy mode.

In addition, in the optical path control member according to theembodiment, the accommodation portion 320 becomes the light transmittingpart in the second mode, and in the optical path control memberaccording to the embodiment, light may be transmitted through both thepartition wall portion 310 and the accommodation portion 320. That is,the viewing angle of the user viewing from the outside may be widened,so that the optical path control member may be driven in a public mode.

Switching from the first mode to the second mode, that is, theconversion of the accommodation portion 320 from the light blocking partto the light transmitting part may be realized by movement of the lightconversion particles 320 b of the accommodation portion 320. That is,the light conversion particles 320 b may have a charge on the surfacethereof and may move toward the first electrode or the second electrodeaccording to the application of a voltage according to characteristicsof the charge. That is, the light conversion particles 320 b may beelectrophoretic particles

In detail, the accommodation portion 320 may be electrically connectedto the first electrode 210 and the second electrode 220.

In this case, when a voltage is not applied to the optical path controlmember from the outside, the light conversion particles 320 b of theaccommodation portion 320 are uniformly dispersed in the dispersionliquid 320 a, and the accommodation portion 320 may block light by thelight conversion particles. Accordingly, in the first mode, theaccommodation portion 320 may be driven as the light blocking part.

Alternatively, when a voltage is applied to the optical path controlmember from the outside, the light conversion particles 320 b may move.For example, the light conversion particles 320 b may move toward oneend or the other end of the accommodation portion 320 by a voltagetransmitted through the first electrode 210 and the second electrode220. That is, the light conversion particles 320 b may move from theaccommodation portion 320 toward the first electrode 210 or the secondelectrode 220.

In detail, when a voltage is applied to the first electrode 210 and/orthe second electrode 220, an electric field is formed between the firstelectrode 210 and the second electrode 220, and the light conversionparticles 320 b charged with the negative charge may move toward apositive electrode of the first electrode 210 and the second electrode220 using the dispersion liquid 320 a as a medium.

That is, when the voltage is applied to the first electrode 210 and/orthe second electrode 220, as shown in FIG. 8 , the light conversionparticles 320 b may move toward the first electrode 210 in thedispersion liquid 320 a. That is, the light conversion particles 320 bmay move in one direction, and the accommodation portion 320 may bedriven as the light transmitting part.

Alternatively, when the voltage is not applied to the first electrode210 and/or the second electrode 220, as shown in FIG. 9 , the lightconversion particles 320 b may be uniformly dispersed in the dispersionliquid 320 a to drive the accommodation portion 320 as the lightblocking part.

Accordingly, the optical path control member according to the embodimentmay be driven in two modes according to a user's surroundingenvironment. That is, when the user requires light transmission only ata specific viewing angle, the accommodation portion is driven as thelight blocking part, or in an environment in which the user requireshigh brightness, a voltage may be applied to drive the accommodationportion as the light transmitting part.

Therefore, since the optical path control member according to theembodiment may be implemented in two modes according to the user'srequirement, the optical path control member may be applied regardlessof the user's environment.

Meanwhile, the accommodation portion may be disposed in a differentshape in consideration of driving characteristics and the like.

Referring to FIGS. 6 and 7 , in an optical path control member accordingto another embodiment, both ends of an accommodation portion 320 may bedisposed in contact with a buffer layer 410 and an adhesive layer 420unlike FIG. 5 .

For example, a lower portion of the accommodation portion 320 may bedisposed in contact with the buffer layer 410, and an upper portion ofthe accommodation portion 320 may be disposed in contact with theadhesive layer 420.

Accordingly, a distance between the accommodation portion 320 and thefirst electrode 210 may be reduced, so that the voltage applied from thefirst electrode 210 may be smoothly transmitted to the accommodationportion 320.

Accordingly, a moving speed of the light conversion particles 320 binside the accommodation portion 320 may be improved, and thus thedriving characteristics of the optical path control member may beimproved.

In addition, referring to FIGS. 8 and 9 , in an optical path controlmember according to an embodiment, unlike FIGS. 6 and 7 , anaccommodation portion 320 may be disposed to have a constant inclinationangle θ.

In detail, referring to FIGS. 8 and 9 , the accommodation portion 320may be disposed to have an inclination angle θ of greater than 0° toless than 90° with respect to the first substrate 110. In detail, theaccommodation portion 320 may extend upward while having an inclinationangle θ of greater than 0° to less than 90° with respect to one surfaceof the first substrate 110.

Accordingly, when the optical path control member is used together witha display panel, moire caused by an overlapping phenomenon between apattern of the display panel and the accommodation portion 320 of theoptical path control member may be alleviated, thereby improving uservisibility.

Hereinafter, improvement of a lateral transmittance of the device byincluding a non-reactive additive in the EPD ink of the embodiment willbe described with reference to FIGS. 10 to 13 .

The light conversion material 320′ may include light conversionparticles and a dispersion liquid.

The light conversion particles may include carbon black.

The dispersion liquid may include an additive and a surfactant. That is,the embodiment may improve the driving performance of the device byincluding the non-reactive additive in the EPD ink.

FIG. 10 is a view showing an example of a principle that the additiveadheres to a surface of the partition wall portion in the dispersionliquid.

The non-reactive additive may include a bond of —Si—. For example, thenon-reactive additive may include a PDMS backbone, thereby includingrepeating bonds of —Si—O—Si—.

When water molecules with a small amount are present in a solvent, asilane group is changed to Si—OH, thereby creating a hydrophobicsurface. For example, Si—X bond of the non-reactive additive included inthe dispersion liquid may react with the water molecules to change intoSi—OH bond.

Polymer aggregates and other microstructures may be positioned aroundthe Si—OH.

In this case, X is illustrated as Cl in FIG. 6A, but the embodiment isnot limited thereto and may include various functional groups. Forexample, in the Si—X bond included in the non-reactive additive, X mayinclude various functional groups including a halogen group such as Fand CH3, an alkyl group, an alkoxy group, a hydroxyl group, an alkenylgroup, an aryl group, and the like.

Meanwhile, the non-reactive additive may include the Si—OH bond. Forexample, when a functional group is bonded to the alkoxy group or thehydroxyl group in PDMS, the non-reactive additive may include the Si—OHbond.

For example, a single layer of a silane surface may be formed on thepartition wall portion by cross-linking between silane groups andsurface adhesion. That is, a micelle may be formed as a monolayer. Whenthe water molecules with a small amount are present in the solvent, thesilane group is hydrolyzed to Si—OH and forms a hydrophobic surface as awhole.

The micelle may have a thickness of 1 nm to 500 nm. For example, themicelle may have a thickness of 1 nm to 300 nm. For example, the micellemay have a thickness of 1 nm to 500 nm. Unlike a core-celle, micellesmay have a thickness of less than 1 μm.

As an example, the non-reactive additive may include —O—Si— bond, and anoxygen element in the —O—Si— bond may form a chemical bond with acomponent of the partition wall portion. For example, oxygen included inthe non-reactive additive may form a covalent bond with an element onthe partition wall portion.

FIG. 11 is a schematic diagram of dispersion of carbon black andformation of micelles.

When an amount of the surfactant in the light conversion material 320′is large, more surfactants may be attached around the carbon black toform micelles. Accordingly, there is a problem that a charge of thecarbon black is reduced and a movement speed is decreased.

Therefore, in the embodiment, the driving performance of the device maybe improved by mixing the EPD ink and the non-reactive additive. Indetail, when a silane component of the non-reactive additive is moved tothe surface of the partition wall portion, a distribution in the solventmay be reduced while forming the surfactant with the micelle in the EPDink.

Accordingly, movement of carbon black particles in the light conversionmaterial may be facilitated. That is, the carbon black particles in thelight conversion material may not be restricted in movement by thesurfactant, so that the lateral transmittance in the share mode may beimproved.

The dispersion liquid may include a micelle formed by reacting thesurfactant with the silane component of the additive.

In the embodiment, various types of micelles may be included. Here, afirst, a second, and a third may be used to distinguish different typesof micelles.

The first micelle may surround the carbon black in the dispersionliquid. For example, the first micelle may be in a form of surroundingcarbon black particles in the dispersion liquid. In detail, the firstmicelle may surround one carbon black particle in the dispersion liquid.Alternatively, the first micelle may surround two or more carbon blackparticles in the dispersion liquid. An anionic material may bepositioned on a surface of the first micelle.

Accordingly, a plurality of carbon black particles may be included inthe dispersion liquid, and each of the plurality of carbon blackparticles may be surrounded by the first micelle again. Therefore, theplurality of carbon black particles in the dispersion liquid may bedispersed by the first micelle.

The second micelle may surround ions in the dispersion liquid. Forexample, the second micelle may surround a cationic material present inthe dispersion liquid.

The first micelle may stabilize anions. On the other hand, the secondmicelle may stabilize cations. That is, ions having different polaritiesmay be stabilized in the dispersion liquid by different micelles.

The third micelle may be attached to the surface of the partition wallportion in the dispersion liquid. In detail, the silane component of thenon-reactive additive in the EPD ink may move to the surface of thepartition wall portion. Accordingly, like a silane surface coating, a—O—Si— component of the non-reactive additive may be bonded to thepartition wall portion. The surfactant in the EPD ink may form themicelle with the silane component of the non-reactive additive.Accordingly, a stacking density of the carbon black particles in theshare mode may be improved, and thus the lateral transmittance of thedevice may be improved.

In addition, since a micelle is formed between surfactant moleculespresent in excess in the EPD ink, and the micelle between suchsurfactant molecules forms the micelle with the silane, a distributionof the surfactant in the EPD ink may be reduced.

The non-reactive additive of the embodiment may form micelles withvarious types of surfactants. For example, an elemental portion of —Si—of the non-reactive additive of the embodiment may be capable of formingmicelles with various types of surfactants. In detail, the surfactantmay form the micelle by itself, regardless of a type, composition,length, molecular weight, functional group, etc. of the surfactant. Thesurfactant's own micelle may have a head portion and a tail portion. Forexample, when the head portion is positioned inside the micelle, thetail portion may be positioned outside the micelle. For example, whenthe tail portion is positioned inside the micelle, the head portion maybe positioned outside the micelle.

For example, as the head portion of the surfactant adheres to aperiphery of —Si— of the non-reactive additive, it may form a micelle.For example, as the head portion of the surfactant adheres to aperiphery of —Si—O— of the non-reactive additive, it may form a micelle.For example, as the head portion of the surfactant adheres to aperiphery of —Si—CH3 of the non-reactive additive, it may form amicelle.

The surfactant will be described in detail with reference to FIGS. 12and 13 .

A structure and type of the surfactant will be described with referenceto FIG. 12 .

In the embodiment, the surfactant may refer to various types ofsurfactants. For example, the surfactant may be at least one of anonionic surfactant, a cationic surfactant and an anionic surfactant,and an amphoteric (zwitterionic) surfactant. Here, the distinctionbetween nonionic, cationic, anionic, and amphoteric properties of thesurfactant may be distinguished through a polarity of the head portion.

One compound constituting the surfactant may include both a hydrophilicportion and a hydrophobic portion. Here, the head of the surfactant mayrefer to a hydrophilic portion of the surfactant. Here, the tail of thesurfactant may refer to a hydrophobic portion of the surfactant.

For example, the surfactant may be any one of Triton X-100, CTAB, AOT,and phosphatidylcholine. Of course, the surfactant of the embodiment isnot limited thereto and may be various types of materials.

FIG. 13 is a view showing a form of a micelle of the surfactant itself.

For example, in the nonionic surfactant, the tail portion may bepositioned inside the micelle and the head portion may be positionedoutside the micelle. In this case, the head portion may show nonionicproperties. For example, in the anionic surfactant, the tail portion maybe positioned inside the micelle and the head portion may be positionedoutside the micelle. In this case, the head portion may show anionicproperties.

In the embodiment, the carbon black particles in the EPD ink may not behindered by the surfactant from reducing the charge, so that the movingspeed may be high. Accordingly, the embodiment may improve a drivingspeed of the device.

Referring to Table 2, an evaluation result of the driving characteristicaccording to the content of the non-reactive additive in the EPD inkwill be described.

Here, a standard for the content of the non-reactive additive refers toa content of the additive compared to a case in which a weight of theEPD ink excluding the additive is 100 wt %.

A type of non-reactive additives may include a fluid (oil), a gum, aresin, and an elastomer.

The fluid may be a linear polymer. For example, the fluid may be aSi-containing material such as polydimethylsiloxane (PDMS).Alternatively, the fluid may be a functional fluid. Here, the functionalfluid may include a material in which a functional group is bonded topolydimethylsiloxane.

The non-reactive additive may include a material in which one or morefunctional groups are bonded to polydimethylsiloxane. The non-reactiveadditive may include a material in which two or more functional groupsthat are the same or different from each other are bonded topolydimethylsiloxane.

The non-reactive additive may be a functional fluid in which afunctional group is bonded to polydimethylsiloxane. In detail, thefunctional group bonded to the backbone of polydimethylsiloxane mayinclude various materials such as alkyl, aryl, allyl, alkenyl, amido,amino, fluoroalkyl, halide, epoxy, carboxyl, hydroxyl, alkoxy,methylhydrogen, and the like. In addition, the copolymer containing Simay include siloxane-urethane copolymer, siloxane-polycaponatecopolymer, siloxane-polyester copolymer, siloxane-polyimide copolymer,acryloxymethylsiloxane, p-styrylsiloxane, copolymer of silicone andaldehyde, polysilformal, and the like.

The non-reactive additive in which a functional group is bonded topolydimethylsiloxane may be an organic modification of a linearpolydimethylsiloxane backbone.

The gum may refer to a linear polymer of ultra-high molecular.

The resin is a polymer having a three-dimensional siloxane structure andmay refer that there are three reactive groups.

The elastomer may be in a state in which silane/siloxane is cross-linkedto form a network.

TABLE 2 Category Comparative Example 2 Example 4 Example 5 Example 6Sample — A-1 A-2 A-3 B-1 B-2 C-1 C-2 C-3 Non-reactive — 0.3 0.5 1 0.30.5 0.3 0.5 1.5 additive (wt %) Device lateral 4.4 33.1 42.3 46.2 36.045.1 39.2 41.8 45.9 transmittance (share mode, %)

Comparative Example 2 is a photocurable resin that does not include anon-reactive additive. Here, the photocurable resin is apolyurethane-based material.

Example 4 is PDMS to which an alkyl-based functional group is bonded.

Example 5 is PDMS to which a fluoroalkayl-based functional group isbonded.

Example 6 is a siloxane-urethane copolymer.

In Examples 4 to 6, as the non-reactive additive is included in anamount of 0.1 wt % to 20 wt % based on 100 wt % of the dispersionliquid, it can be confirmed that the lateral transmittance of the devicemeasured in the share mode is 30% or more.

For example, in the embodiment, the non-reactive additive may beincluded in an amount of 0.1 wt % to 10 wt % based on 100 wt % of thedispersion liquid, and thus it can be confirmed that the lateraltransmittance of the device measured in the share mode is 30% or more.

For example, in the embodiment, the non-reactive additive may beincluded in an amount of 0.1 wt % to 5 wt % based on 100 wt % of thedispersion liquid, and thus it can be confirmed that the lateraltransmittance of the device measured in the share mode is 30% or more.

Here, the lateral transmittance is measured in the share mode and mayrefer to a luminance value measured when the device is positioned at 45degrees. That is, the lateral transmittance is that the luminance valueof the device positioned at the 45 degrees is measured in a measuringdevice.

That is, in the present invention, the non-reactive additive may becontained in the EPD ink in order to improve the driving speed of thedevice. Accordingly, dispersibility between carbon black particles inthe EPD ink may be improved. In addition, the driving speed may beimproved due to the ease of movement of the carbon black in the EPD ink.In addition, the lateral transmittance of the device in the share modemay be improved.

Meanwhile, the EPD ink according to the embodiment may include only asurfactant.

In detail, the EPD ink may include a surfactant that reacts with thenon-reactive additive.

In addition, the non-reactive additive reacting with the surfactant maybe disposed on the partition wall portion. In detail, the non-reactiveadditive that reacts with the surfactant to form the micelle may bedisposed on the surface of the partition wall portion. In more detail,the non-reactive additive that reacts with the surfactant to form themicelle may be formed on the surface of the partition wall portion.

Therefore, the embodiment may improve the driving performance of thedevice by disposing the non-reactive additive on the surface of thepartition wall portion in contact with the EPD ink. In detail, thenon-reactive additive on the surface of the partition wall portion mayreduce the distribution in the solvent while forming the micelle withthe surfactant in the EPD ink.

That is, the surfactant in the EPD ink may form the micelle with thesilane component of the non-reactive additive. Accordingly, the stackingdensity of carbon black particles in the share mode may be improved, andthus the lateral transmittance of the device may be improved.

Hereinafter, a method of manufacturing an optical path control memberaccording to an embodiment will be described with reference to FIGS. 14to 20 .

Referring to FIG. 14 , a first substrate 110 and an electrode materialfor forming a first electrode are prepared. Then, the first electrodemay be formed by coating or depositing the electrode material on onesurface of the first substrate. In detail, the electrode material may beformed on the entire surface of the first substrate 110. Accordingly,the first electrode 210 formed as a surface electrode may be formed onthe first substrate 110.

Subsequently, referring to FIG. 15 , a resin layer 350 may be formed bycoating a resin material on the first electrode 210. In detail, theresin layer 350 may be formed by applying a urethane resin or an acrylicresin on the first electrode 210.

In this case, before disposing the resin layer 350, a buffer layer 410may be additionally disposed on the first electrode 210. In detail, bydisposing the resin layer 350 on the buffer layer 410 after disposingthe buffer layer 410 having good adhesion to the resin layer 350 on thefirst electrode 210, it is possible to improve the adhesion of the resinlayer 350.

For example, the buffer layer 410 may include an organic materialincluding a lipophilic group such as —CH—, an alkyl group, etc. Havinggood adhesion to the electrode and a hydrophilic group such as —NH, —OH,—COOH, etc. Having a good adhesion to the resin layer 410.

The resin layer 350 may be disposed on a partial region of the firstsubstrate 110. That is, the resin layer 350 may be disposed in an areasmaller than that of the first substrate 110. Accordingly, a regionwhere the resin layer 350 is not disposed and the first electrode 210 isexposed may be formed on the first substrate 110. In addition, when thebuffer layer 410 is disposed on the first electrode 210, a region wherethe buffer layer 410 is exposed may be formed.

In detail, a size of a third length extending in the first direction ofthe resin layer 350 may be less than a size of a first length extendingin the first direction of the first substrate 110, and a size of a thirdwidth extending in the second direction may be less than or equal to asize of a first width extending in the second direction of the firstsubstrate 110.

That is, a length of the resin layer 350 may be smaller than a length ofthe first substrate 110, and a width of the resin layer 350 may be equalto or smaller than a width of the first substrate 110.

Subsequently, referring to FIG. 16 , the resin layer 350 may bepatterned to form a plurality of partition wall portions 310 and aplurality of accommodation portions 320 in the resin layer 350. Indetail, an engraved portion may be formed in the resin layer 350 to forman engrave-shaped accommodation portion 320 and the emboss-shapedpartition wall portion 310 between the engraved portions.

Accordingly, a light conversion part 300 including the partition wallportion 310 and the accommodation portion 320 may be formed on the firstsubstrate 110.

In addition, the buffer layer 410 exposed on the first electrode 210 maybe removed to expose the first electrode 210 in a region where the firstsubstrate 110 protrudes.

Subsequently, referring to FIG. 17 , a second electrode and an electrodematerial for forming a second substrate 120 and are prepared. Then, thesecond electrode may be formed by coating or depositing the electrodematerial on one surface of the second substrate. In detail, theelectrode material may be formed on the entire surface of the secondsubstrate 120. Accordingly, the second electrode 220 formed as a surfaceelectrode may be formed on the second substrate 120.

A size of the second substrate 120 may be smaller than that of the firstsubstrate 110. In addition, the size of the second substrate 120 may besmaller than that of the resin layer 350.

In detail, a size of a second length extending in a first direction ofthe second substrate 120 may be greater than the third length extendingin the first direction of the resin layer 350, and a size of a secondwidth extending in a second direction of the second substrate 120 may besmaller than the size of the third width extending in the seconddirection of the resin layer 350.

Subsequently, referring to FIG. 18 , an adhesive layer 420 may be formedby coating an adhesive material on the second electrode 220. In detail,a light-transmitting adhesive layer capable of transmitting light may beformed on the second electrode 220. For example, the adhesive layer 420may include an optical transparent adhesive layer OCA.

The adhesive layer 420 may be disposed on a partial region of the lightconversion part 300. That is, the adhesive layer 420 may be disposed inan area smaller than that of the light conversion part 300. Accordingly,a region where the adhesive layer 410 is not disposed and the lightconversion part 300 is exposed may be formed on the light conversionpart 300.

In detail, a size of a fourth length extending in a first direction ofthe adhesive layer 420 may be greater than a size of a third lengthextending in a first direction of the light conversion part 300, and asize of a fourth width extending in a second direction of the adhesivelayer 420 may be smaller than a size of a third width extending in asecond direction of the light conversion part 300.

Subsequently, referring to FIG. 19 , the first substrate 110 and thesecond substrate 120 may be adhered. In detail, the second substrate 120may be disposed on the light conversion part 300, and the secondsubstrate 120 and the light conversion part 300 may be adhered throughthe adhesive layer 420 disposed under the second substrate 120.

Accordingly, the first substrate 110, the light conversion part 300, andthe second substrate 120 may be sequentially stacked in the thicknessdirection of the first substrate 110, the light conversion part 300, andthe second substrate 120.

In this case, since the second substrate 120 is disposed in a sizesmaller than the size of the resin layer 350, a plurality of partitionwall portions 310 and accommodation portions 320 may be exposed in aregion where the second substrate 120 is not disposed on the lightconversion part 300.

In detail, since the size of the second width extending in the seconddirection of the second substrate 120 is smaller than the size of thethird width extending in the second direction of the resin layer 350,the plurality of partition walls 310 and the accommodation portion 320may be exposed in an end region of at least one of one end and the otherend facing in a width direction of the resin layer 350.

Subsequently, a light conversion material 380 may be injected betweenthe partition wall portions 310, that is, the accommodation portions320. In detail, a light conversion material in which light absorbingparticles such as carbon black are dispersed in an electrolyte solventincluding a paraffinic solvent and the like may be injected between thepartition wall portions, that is, the accommodation portions 320.

For example, after disposing a dam extending in a longitudinal directionof the light conversion part 300 on the accommodation portion and thepartition wall portion of the light conversion part 300 on which thesecond substrate 120 is not disposed, the electrolyte solvent may beinjected into the accommodation portion 320 by a capillary injectionmethod between the dam and a side surface of the light conversion part300.

Subsequently, one optical path control member may be manufactured bycutting the light conversion part 300. In detail, the light conversionpart 300 may be cut in a longitudinal direction of the light conversionpart 300. That is, the light conversion part 300, the buffer layer 410under the light conversion part 300, the first electrode 210, and thefirst substrate 110 may be cut along the dotted line shown in FIG. 19 .A plurality of optical path control members A and B may be formed by thecutting process, and FIG. 20 is a view showing one of the plurality ofoptical path control members.

In detail, the light conversion part 300 may be cut so that sidesurfaces of the first substrate 110, the second substrate 120, and thelight conversion part 300 in the width direction may be disposed on thesame plane.

Accordingly, both ends of the second substrate 120, the second electrode220, or the adhesive layer 420 in the second direction and both ends ofthe light conversion part 300 in the second direction may be disposed onthe same plane.

That is, the both ends of the adhesive layer 420 in the second directionand the both ends of the light conversion part 300 in the seconddirection may be connected to each other.

Alternatively, the both ends of the second substrate 120, the secondelectrode 220, or the adhesive layer 420 in the second direction may bedisposed more outside than the both ends of the light conversion part300 in the second direction according to an error during the process.

Subsequently, the buffer layer 410 disposed on the first substrate 110and/or the adhesive layer 420 disposed under the second substrate 120may be partially removed to form a connection portion in which theelectrode is exposed. In detail, when the buffer layer 410 is disposedon the first electrode where the light conversion part 300 is notdisposed on an upper surface of the first substrate 110, a firstconnection portion 211 may be formed on the first substrate 110 byremoving a part of the first buffer layer 410 to expose the firstelectrode 210 or by not disposing the buffer layer 410 on the firstelectrode on which the light conversion unit 300 is not disposed fromthe beginning. In addition, when the adhesive layer 420 is disposed onthe second electrode where the light conversion part 300 is not disposedon a lower surface of the second substrate 120, a second connectionportion 221 may be formed under the second substrate 120 by removing apart of the adhesive layer 420 or by not disposing the adhesive layer onthe second electrode on which the light conversion part 300 is notdisposed during the adhesive process.

A printed circuit board or a flexible printed circuit board may beconnected to the connection portions through an anisotropic conductivefilm (ACF) or the like, and the printed circuit board may be connectedto an external power source to apply a voltage to the optical pathcontrol member.

Hereinafter, referring to FIGS. 21 to 25 , a display device to which anoptical path control member according to an embodiment is applied willbe described.

Referring to FIGS. 21 and 22 , an optical path control member 1000according to an embodiment may be disposed on or under a display panel2000.

The display panel 2000 and the optical path control member 1000 may bedisposed to be adhered to each other. For example, the display panel2000 and the optical path control member 1000 may be adhered to eachother via an adhesive layer 1500. The adhesive layer 1500 may betransparent. For example, the adhesive layer 1500 may include anadhesive or an adhesive layer including an optical transparent adhesivematerial.

The adhesive layer 1500 may include a release film. In detail, whenadhering the optical path control member and the display panel, theoptical path control member and the display panel may be adhered afterthe release film is removed.

Meanwhile, referring to FIGS. 21 and 22 , one end or one end and theother end of the optical path control member may protrude, and the lightconversion part may not be disposed at the protruding portion. Theprotrusion region is an electrode connection portion in which the firstelectrode 210 and the second electrode 220 are exposed, and may connectan external printed circuit board and the optical path control memberthrough the electrode connection portion.

The display panel 2000 may include a first′ substrate 2100 and a second′substrate 2200. When the display panel 2000 is a liquid crystal displaypanel, the optical path control member may be formed under the liquidcrystal panel. That is, when a surface viewed by the user in the liquidcrystal panel is defined as an upper portion of the liquid crystalpanel, the optical path control member may be disposed under the liquidcrystal panel. The display panel 2000 may be formed in a structure inwhich the first′ substrate 2100 including a thin film transistor (TFT)and a pixel electrode and the second′ substrate 2200 including colorfilter layers are bonded to each other with a liquid crystal layerinterposed therebetween.

In addition, the display panel 2000 may be a liquid crystal displaypanel of a color filter on transistor (COT) structure in which a thinfilm transistor, a color filter, and a black electrolyte are formed atthe first′ substrate 2100 and the second′ substrate 2200 is bonded tothe first′ substrate 2100 with the liquid crystal layer interposedtherebetween. That is, a thin film transistor may be formed on thefirst′ substrate 2100, a protective film may be formed on the thin filmtransistor, and a color filter layer may be formed on the protectivefilm. In addition, a pixel electrode in contact with the thin filmtransistor may be formed on the first′ substrate 2100. At this point, inorder to improve an aperture ratio and simplify a masking process, theblack electrolyte may be omitted, and a common electrode may be formedto function as the black electrolyte.

In addition, when the display panel 2000 is the liquid crystal displaypanel, the display device may further include a backlight unit 3000providing light from a rear surface of the display panel 2000.

That is, as shown in FIG. 21 , the optical path control member may bedisposed under the liquid crystal panel and on the backlight unit 3000,and the optical path control member may be disposed between thebacklight unit 3000 and the display panel 2000.

Alternatively, as shown in FIG. 22 , when the display panel 2000 is anorganic light emitting diode panel, the optical path control member maybe formed on the organic light emitting diode panel. That is, when thesurface viewed by the user in the organic light emitting diode panel isdefined as an upper portion of the organic light emitting diode panel,the optical path control member may be disposed on the organic lightemitting diode panel. The display panel 2000 may include a self-luminouselement that does not require a separate light source. In the displaypanel 2000, a thin film transistor may be formed on the first′ substrate2100, and an organic light emitting element in contact with the thinfilm transistor may be formed. The organic light emitting element mayinclude an anode, a cathode, and an organic light emitting layer formedbetween the anode and the cathode. In addition, the second′ substrate2200 configured to function as an encapsulation substrate forencapsulation may be further included on the organic light emittingelement.

That is, light emitted from the display panel 2000 or the backlight unit3000 may move from the second substrate 120 toward the first substrate110 of the optical path control member.

In addition, although not shown in drawings, a polarizing plate may befurther disposed between the optical path control member 1000 and thedisplay panel 2000. The polarizing plate may be a linear polarizingplate or an external light reflection preventive polarizing plate. Forexample, when the display panel 2000 is a liquid crystal display panel,the polarizing plate may be the linear polarizing plate. Further, whenthe display panel 2000 is the organic light emitting diode panel, thepolarizing plate may be the external light reflection preventingpolarizing plate.

In addition, an additional functional layer 1300 such as ananti-reflection layer, an anti-glare, or the like may be furtherdisposed on the optical path control member 1000. In detail, thefunctional layer 1300 may be adhered to one surface of the firstsubstrate 110 of the optical path control member. Although not shown indrawings, the functional layer 1300 may be adhered to the firstsubstrate 110 of the optical path control member via an adhesive layer.In addition, a release film for protecting the functional layer may befurther disposed on the functional layer 1300.

Further, a touch panel may be further disposed between the display paneland the optical path control member.

It is shown in the drawings that the optical path control member isdisposed at an upper portion of the display panel, but the embodiment isnot limited thereto, and the optical path control member may be disposedat various positions such as a position in which light is adjustable,that is, a lower portion of the display panel, or between a secondsubstrate and a first substrate of the display panel, or the like.

In addition, it is shown in the drawings that the light conversion partof the optical path control member according to the embodiment is in adirection parallel or perpendicular to an outer surface of the secondsubstrate, but the light conversion part is formed to be inclined at apredetermined angle from the outer surface of the second substrate.Through this, a moire phenomenon occurring between the display panel andthe optical path control member may be reduced.

Referring to FIGS. 23 to 25 , an optical path control member accordingto an embodiment may be applied to various display devices.

Referring to FIGS. 23 to 25 , the optical path control member accordingto the embodiment may be applied to a display device that displays adisplay.

For example, when power is applied to the optical path control member asshown in FIG. 23 , the accommodation portion functions as the lighttransmitting part, so that the display device may be driven in thepublic mode, and when power is not applied to the optical path controlmember as shown in FIG. 24 , the accommodation portion functions as thelight blocking part, so that the display device may be driven in thelight blocking mode.

Accordingly, a user may easily drive the display device in a privacymode or a normal mode according to application of power.

Light emitted from the backlight unit or the self-luminous element maymove from the first substrate toward the second substrate.Alternatively, the light emitted from the backlight unit or theself-luminous element may also move from the second substrate toward thefirst substrate.

In addition, referring to FIG. 25 , the display device to which theoptical path control member according to the embodiment is applied mayalso be applied inside a vehicle.

For example, the display device including the optical path controlmember according to the embodiment may display a video confirminginformation of the vehicle and a movement route of the vehicle. Thedisplay device may be disposed between a driver seat and a passengerseat of the vehicle.

In addition, the optical path control member according to the embodimentmay be applied to a dashboard that displays a speed, an engine, an alarmsignal, and the like of the vehicle.

Further, the optical path control member according to the embodiment maybe applied to a front glass (FG) of the vehicle or right and left windowglasses.

The characteristics, structures, effects, and the like described in theabove-described embodiments are included in at least one embodiment ofthe present invention, but are not limited to only one embodiment.Furthermore, the characteristic, structure, and effect illustrated ineach embodiment may be combined or modified for other embodiments by aperson skilled in the art. Accordingly, it is to be understood that suchcombination and modification are included in the scope of the presentinvention.

In addition, embodiments are mostly described above, but the embodimentsare merely examples and do not limit the present invention, and a personskilled in the art may appreciate that several variations andapplications not presented above may be made without departing from theessential characteristic of embodiments. For example, each componentspecifically shown in the embodiments may be modified and implemented.In addition, it should be construed that differences related to such avariation and such an application are included in the scope of thepresent invention defined in the following claims.

1-10. (canceled)
 11. An optical path control member comprising: a firstsubstrate; a first electrode disposed on the first substrate; a lightconversion part disposed on the first electrode; a second substratedisposed on the first substrate; a second electrode disposed under thesecond substrate; and an adhesive layer disposed between the lightconversion part and the second electrode, wherein the light conversionpart includes a partition wall portion and an accommodation portionalternately disposed, the accommodation portion has a lighttransmittance that changes according to application of a voltage, anupper surface of the partition wall portion is in contact with theadhesive layer, the light conversion part is formed of a photocurableresin, the photocurable resin includes an oligomer, a monomer, aphotopolymerization initiator, and an additive, the additive includes anantistatic agent, and when a weight of the photocurable resin is 100 wt%, the additive is included in an amount of 2.0 wt % to 3.0 wt %. 12.The optical path control member of claim 11, wherein the antistaticagent includes at least one of a nonionic surfactant, a cationicsurfactant, an anionic surfactant, and an amphoteric surfactant.
 13. Theoptical path control member of claim 12, wherein the nonionic surfactantincludes an amine-based surfactant and a glycerin-based surfactant, thecationic surfactant includes a quaternary ammonium salt, the anionicsurfactant includes sulfonate and phosphate, and the amphotericsurfactant includes betaine.
 14. The optical path control member ofclaim 11, wherein the additive further includes a non-reactive releaseadditive.
 15. The optical path control member of claim 14, wherein thenon-reactive release additive is included in an amount of 0.3 wt % orless.
 16. The optical path control member of claim 14, wherein thenon-reactive release additive is included in an amount of 0.1 wt % to0.3 wt %.
 17. The optical path control member of claim 14, wherein thenon-reactive release additive includes a material in which a functionalgroup is bonded to polydimethylsiloxane.
 18. The optical path controlmember of claim 16, wherein the functional group includes an alkylgroup, an aryl group, an allyl group, an alkenyl group, an amido group,an amino group, a fluoroalkyl group, a halide group, an epoxy group, acarboxy group, a hydroxyl group or an alkoxy group, and methylhydrogen.19. The optical path control member of claim 11, wherein haze of thelight conversion part is 9% or less.
 20. The optical path control memberof claim 11, wherein a lateral transmittance of the light conversionpart is 30% or more.
 21. The optical path control member of claim 11,wherein the photo-curable resin includes urethane acrylate, acrylatemonomers, isobornyl acrylate, additives, photoinitiators, andacryloylmorpholine.
 22. The optical path control member of claim 14,wherein the antistatic agent and the non-reactive release additive areincluded in an amount of 2.4 wt % to 2.8 wt %.
 23. The optical pathcontrol member of claim 11, wherein the accommodation portionaccommodates light conversion particles and a dispersion liquid, thelight conversion particles include carbon black, and the dispersionliquid includes a surfactant reacting with the additive.
 24. The opticalpath control member of claim 23, wherein the surfactant includes atleast one of a nonionic surfactant, a cationic surfactant, and ananionic surfactant, and an amphoteric surfactant.
 25. The optical pathcontrol member of claim 23, wherein the light conversion particles movein a direction of the first electrode or the second electrode by anapplied voltage.
 26. A display device comprising: a display panel; andthe optical path control member according to claim 11 disposed on thedisplay panel.